1
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Graf J, Fresenborg L, Seitz HM, Pernil R, Schleiff E. A cobalt concentration sensitive Btu-like system facilitates cobalamin uptake in Anabaena sp. PCC 7120. MICROBIAL CELL (GRAZ, AUSTRIA) 2024; 11:41-56. [PMID: 38379927 PMCID: PMC10878165 DOI: 10.15698/mic2024.02.814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/21/2023] [Accepted: 01/09/2024] [Indexed: 02/22/2024]
Abstract
Metal homeostasis is central to all forms of life, as metals are essential micronutrients with toxic effects at elevated levels. Macromolecular machines facilitate metal uptake into the cells and their intracellular level is regulated by multiple means, which can involve RNA elements and proteinaceous components. While the general principles and components for uptake and cellular content regulation of, e.g., cobalt have been identified for proteobacteria, the corresponding mechanism in other Gram-negative bacteria such as cyanobacteria remain to be established. Based on their photosynthetic activity, cyanobacteria are known to exhibit a special metal demand in comparison to other bacteria. Here, the regulation by cobalt and cobalamin as well as their uptake is described for Anabaena sp. PCC 7120, a model filamentous heterocyst-forming cyanobacterium. Anabaena contains at least three cobalamin riboswitches in its genome, for one of which the functionality is confirmed here. Moreover, two outer membrane-localized cobalamin TonB-dependent transporters, namely BtuB1 and BtuB2, were identified. BtuB2 is important for fast uptake of cobalamin under conditions with low external cobalt, whereas BtuB1 appears to function in cobalamin uptake under conditions of sufficient cobalt supply. While the general function is comparable, the specific function of the two genes differs and mutants thereof show distinct phenotypes. The uptake of cobalamin depends further on the TonB and a BtuFCD machinery, as mutants of tonB3 and btuD show reduced cobalamin uptake rates. Thus, our results provide novel information on the uptake of cobalamin and the regulation of the cellular cobalt content in cyanobacteria.
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Affiliation(s)
- Julia Graf
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
| | - Leonard Fresenborg
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
- Frankfurt Isotope and Element Research Center, Goethe University Frankfurt, 60438 Frankfurt Germany
| | - Hans-Michael Seitz
- Frankfurt Isotope and Element Research Center, Goethe University Frankfurt, 60438 Frankfurt Germany
- Institute for Geoscience, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt, Germany
| | - Rafael Pernil
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
- Frankfurt Isotope and Element Research Center, Goethe University Frankfurt, 60438 Frankfurt Germany
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straβe 1, 60438 Frankfurt, Germany
- Buchmann Institute for Molecular Life Sciences, Max von Laue Str. 11, 60438 Frankfurt, Germany
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2
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Kolan D, Cattan-Tsaushu E, Enav H, Freiman Z, Malinsky-Rushansky N, Ninio S, Avrani S. Tradeoffs between phage resistance and nitrogen fixation drive the evolution of genes essential for cyanobacterial heterocyst functionality. THE ISME JOURNAL 2024; 18:wrad008. [PMID: 38365231 PMCID: PMC10811720 DOI: 10.1093/ismejo/wrad008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 10/26/2023] [Accepted: 11/13/2023] [Indexed: 02/18/2024]
Abstract
Harmful blooms caused by diazotrophic (nitrogen-fixing) Cyanobacteria are becoming increasingly frequent and negatively impact aquatic environments worldwide. Cyanophages (viruses infecting Cyanobacteria) can potentially regulate cyanobacterial blooms, yet Cyanobacteria can rapidly acquire mutations that provide protection against phage infection. Here, we provide novel insights into cyanophage:Cyanobacteria interactions by characterizing the resistance to phages in two species of diazotrophic Cyanobacteria: Nostoc sp. and Cylindrospermopsis raciborskii. Our results demonstrate that phage resistance is associated with a fitness tradeoff by which resistant Cyanobacteria have reduced ability to fix nitrogen and/or to survive nitrogen starvation. Furthermore, we use whole-genome sequence analysis of 58 Nostoc-resistant strains to identify several mutations associated with phage resistance, including in cell surface-related genes and regulatory genes involved in the development and function of heterocysts (cells specialized in nitrogen fixation). Finally, we employ phylogenetic analyses to show that most of these resistance genes are accessory genes whose evolution is impacted by lateral gene transfer events. Together, these results further our understanding of the interplay between diazotrophic Cyanobacteria and their phages and suggest that a tradeoff between phage resistance and nitrogen fixation affects the evolution of cell surface-related genes and of genes involved in heterocyst differentiation and nitrogen fixation.
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Affiliation(s)
- Dikla Kolan
- Department of Evolutionary and Environmental Biology, The Institute of Evolution, University of Haifa, Mount Carmel, Haifa 3103301, Israel
| | - Esther Cattan-Tsaushu
- Department of Evolutionary and Environmental Biology, The Institute of Evolution, University of Haifa, Mount Carmel, Haifa 3103301, Israel
| | - Hagay Enav
- Department of Evolutionary and Environmental Biology, The Institute of Evolution, University of Haifa, Mount Carmel, Haifa 3103301, Israel
| | - Zohar Freiman
- Kinneret Limnological Laboratory (KLL) Israel Oceanographic and Limnological Research (IOLR), Migdal 1495000, Israel
| | - Nechama Malinsky-Rushansky
- Kinneret Limnological Laboratory (KLL) Israel Oceanographic and Limnological Research (IOLR), Migdal 1495000, Israel
| | - Shira Ninio
- Kinneret Limnological Laboratory (KLL) Israel Oceanographic and Limnological Research (IOLR), Migdal 1495000, Israel
| | - Sarit Avrani
- Department of Evolutionary and Environmental Biology, The Institute of Evolution, University of Haifa, Mount Carmel, Haifa 3103301, Israel
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3
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Xing WY, Liu J, Zhang CC. HetF defines a transition point from commitment to morphogenesis during heterocyst differentiation in the cyanobacterium Anabaena sp. PCC 7120. Mol Microbiol 2023; 120:740-753. [PMID: 37804047 DOI: 10.1111/mmi.15177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/16/2023] [Accepted: 09/22/2023] [Indexed: 10/08/2023]
Abstract
The filamentous cyanobacterium Anabaena sp. PCC 7120 is able to form heterocysts for nitrogen fixation. Heterocyst differentiation is initiated by combined-nitrogen deprivation, followed by the commitment step during which the developmental process becomes irreversible. Mature heterocysts are terminally differentiated cells unable to divide, and cell division is required for heterocyst differentiation. Previously, we have shown that the HetF protease regulates cell division and heterocyst differentiation by cleaving PatU3, which is an inhibitor for both events. When hetF is required during the developmental program remains unknown. Here, by controlling the timing of hetF expression during heterocyst differentiation, we provide evidence that hetF is required just before the beginning of heterocyst morphogenesis. Consistent with this finding, transcriptome data show that most of the genes known to be involved in the early step (such as hetR and ntcA) or the commitment step (such as hetP and hetZ) of heterocyst development could be expressed in the ΔhetF mutant. In contrast, most of the genes involved in heterocyst morphogenesis and nitrogen fixation remain repressed in the mutant. These results indicated that in the absence of hetF, heterocyst differentiation is able to be initiated and proceeds to the stage just before heterocyst envelope formation.
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Affiliation(s)
- Wei-Yue Xing
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, People's Republic of China
| | - Jing Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, People's Republic of China
| | - Cheng-Cai Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, People's Republic of China
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4
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Doppler P, Kriechbaum R, Spadiut O. High-throughput characterization of the filamentous cyanobacterium Anabaena sp. using flow cytometry. J Microbiol Methods 2022; 199:106510. [PMID: 35697185 DOI: 10.1016/j.mimet.2022.106510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 12/27/2022]
Abstract
In stirred-tank photobioreactors agitation causes fragmentation of filamentous cyanobacteria. Here, we introduce a flow cytometric approach for high-throughput measurements of trichome dimensions, heterocysts and metabolic activity of Anabaena sp. cultures. The longest characterized trichome had 1135 μm chain length. This technology could potentially be used for monitoring and control purposes.
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Affiliation(s)
- Philipp Doppler
- Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria.
| | - Ricarda Kriechbaum
- Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria.
| | - Oliver Spadiut
- Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria.
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5
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Abstract
Heterocyst differentiation that occurs in some filamentous cyanobacteria, such as Anabaena sp. PCC 7120, provides a unique model for prokaryotic developmental biology. Heterocyst cells are formed in response to combined-nitrogen deprivation and possess a microoxic environment suitable for nitrogen fixation following extensive morphological and physiological reorganization. A filament of Anabaena is a true multicellular organism, as nitrogen and carbon sources are exchanged among different cells and cell types through septal junctions to ensure filament growth. Because heterocysts are terminally differentiated cells and unable to divide, their activity is an altruistic behavior dedicated to providing fixed nitrogen for neighboring vegetative cells. Heterocyst development is also a process of one-dimensional pattern formation, as heterocysts are semiregularly intercalated among vegetative cells. Morphogens form gradients along the filament and interact with each other in a fashion that fits well into the Turing model, a mathematical framework to explain biological pattern formation. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Xiaoli Zeng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China; ,
| | - Cheng-Cai Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China; , .,Institut WUT-AMU, Aix-Marseille Université and Wuhan University of Technology, Wuhan, Hubei, China.,Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
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6
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Flores E, Romanovicz DK, Nieves-Morión M, Foster RA, Villareal TA. Adaptation to an Intracellular Lifestyle by a Nitrogen-Fixing, Heterocyst-Forming Cyanobacterial Endosymbiont of a Diatom. Front Microbiol 2022; 13:799362. [PMID: 35369505 PMCID: PMC8969518 DOI: 10.3389/fmicb.2022.799362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/22/2022] [Indexed: 11/13/2022] Open
Abstract
The symbiosis between the diatom Hemiaulus hauckii and the heterocyst-forming cyanobacterium Richelia intracellularis makes an important contribution to new production in the world's oceans, but its study is limited by short-term survival in the laboratory. In this symbiosis, R. intracellularis fixes atmospheric dinitrogen in the heterocyst and provides H. hauckii with fixed nitrogen. Here, we conducted an electron microscopy study of H. hauckii and found that the filaments of the R. intracellularis symbiont, typically composed of one terminal heterocyst and three or four vegetative cells, are located in the diatom's cytoplasm not enclosed by a host membrane. A second prokaryotic cell was also detected in the cytoplasm of H. hauckii, but observations were infrequent. The heterocysts of R. intracellularis differ from those of free-living heterocyst-forming cyanobacteria in that the specific components of the heterocyst envelope seem to be located in the periplasmic space instead of outside the outer membrane. This specialized arrangement of the heterocyst envelope and a possible association of the cyanobacterium with oxygen-respiring mitochondria may be important for protection of the nitrogen-fixing enzyme, nitrogenase, from photosynthetically produced oxygen. The cell envelope of the vegetative cells of R. intracellularis contained numerous membrane vesicles that resemble the outer-inner membrane vesicles of Gram-negative bacteria. These vesicles can export cytoplasmic material from the bacterial cell and, therefore, may represent a vehicle for transfer of fixed nitrogen from R. intracellularis to the diatom's cytoplasm. The specific morphological features of R. intracellularis described here, together with its known streamlined genome, likely represent specific adaptations of this cyanobacterium to an intracellular lifestyle.
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Affiliation(s)
- Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC, Universidad de Sevilla, Seville, Spain
| | - Dwight K Romanovicz
- Department of Psychology, The University of Texas at Austin, Austin, TX, United States
| | - Mercedes Nieves-Morión
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC, Universidad de Sevilla, Seville, Spain
| | - Rachel A Foster
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Tracy A Villareal
- Department of Marine Science and Marine Science Institute, The University of Texas at Austin, Port Aransas, TX, United States
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7
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Xu C, Wang B, Heng H, Huang J, Wan C. Comparative Network Biology Discovers Protein Complexes That Underline Cellular Differentiation in Anabaena sp. Mol Cell Proteomics 2022; 21:100224. [PMID: 35288331 PMCID: PMC9035410 DOI: 10.1016/j.mcpro.2022.100224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 02/20/2022] [Accepted: 03/10/2022] [Indexed: 01/11/2023] Open
Abstract
The filamentous cyanobacterium Anabaena sp. PCC 7120 can differentiate into heterocysts to fix atmospheric nitrogen. During cell differentiation, cellular morphology and gene expression undergo a series of significant changes. To uncover the mechanisms responsible for these alterations, we built protein–protein interaction (PPI) networks for these two cell types by cofractionation coupled with mass spectrometry. We predicted 280 and 215 protein complexes, with 6322 and 2791 high-confidence PPIs in vegetative cells and heterocysts, respectively. Most of the proteins in both types of cells presented similar elution profiles, whereas the elution peaks of 438 proteins showed significant changes. We observed that some well-known complexes recruited new members in heterocysts, such as ribosomes, diflavin flavoprotein, and cytochrome c oxidase. Photosynthetic complexes, including photosystem I, photosystem II, and phycobilisome, remained in both vegetative cells and heterocysts for electron transfer and energy generation. Besides that, PPI data also reveal new functions of proteins. For example, the hypothetical protein Alr4359 was found to interact with FraH and Alr4119 in heterocysts and was located on heterocyst poles, thereby influencing the diazotrophic growth of filaments. The overexpression of Alr4359 suspended heterocyst formation and altered the pigment composition and filament length. This work demonstrates the differences in protein assemblies and provides insight into physiological regulation during cell differentiation. PPIs in two types of cells of Anabaena sp. 7120 were systematically identified. 10,302 and 8557 high-confidence PPIs were obtained and over 80% were novel. About 438 proteins showed significant changes in vegetative cells and heterocysts. Protein Alr4359 was found to influence the diazotrophic growth of filaments.
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Affiliation(s)
- Chen Xu
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, China
| | - Bing Wang
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, China
| | - Hailu Heng
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, China
| | - Jiangmei Huang
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, China
| | - Cuihong Wan
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, China.
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8
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Mallén-Ponce MJ, Huertas MJ, Florencio FJ. Exploring the Diversity of the Thioredoxin Systems in Cyanobacteria. Antioxidants (Basel) 2022; 11:antiox11040654. [PMID: 35453339 PMCID: PMC9025218 DOI: 10.3390/antiox11040654] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 02/04/2023] Open
Abstract
Cyanobacteria evolved the ability to perform oxygenic photosynthesis using light energy to reduce CO2 from electrons extracted from water and form nutrients. These organisms also developed light-dependent redox regulation through the Trx system, formed by thioredoxins (Trxs) and thioredoxin reductases (TRs). Trxs are thiol-disulfide oxidoreductases that serve as reducing substrates for target enzymes involved in numerous processes such as photosynthetic CO2 fixation and stress responses. We focus on the evolutionary diversity of Trx systems in cyanobacteria and discuss their phylogenetic relationships. The study shows that most cyanobacteria contain at least one copy of each identified Trx, and TrxA is the only one present in all genomes analyzed. Ferredoxin thioredoxin reductase (FTR) is present in all groups except Gloeobacter and Prochlorococcus, where there is a ferredoxin flavin-thioredoxin reductase (FFTR). Our data suggest that both TRs may have coexisted in ancestral cyanobacteria together with other evolutionarily related proteins such as NTRC or DDOR, probably used against oxidative stress. Phylogenetic studies indicate that they have different evolutionary histories. As cyanobacteria diversified to occupy new habitats, some of these proteins were gradually lost in some groups. Finally, we also review the physiological relevance of redox regulation in cyanobacteria through the study of target enzymes.
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Affiliation(s)
- Manuel J. Mallén-Ponce
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Sevilla, Spain;
- Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Biología, Universidad de Sevilla, Profesor García González s/n, 41012 Sevilla, Spain
- Correspondence: (M.J.M.-P.); (M.J.H.)
| | - María José Huertas
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Sevilla, Spain;
- Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Biología, Universidad de Sevilla, Profesor García González s/n, 41012 Sevilla, Spain
- Correspondence: (M.J.M.-P.); (M.J.H.)
| | - Francisco J. Florencio
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Sevilla, Spain;
- Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Biología, Universidad de Sevilla, Profesor García González s/n, 41012 Sevilla, Spain
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9
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Perin G, Fletcher T, Sagi-Kiss V, Gaboriau DCA, Carey MR, Bundy JG, Jones PR. Calm on the surface, dynamic on the inside. Molecular homeostasis of Anabaena sp. PCC 7120 nitrogen metabolism. PLANT, CELL & ENVIRONMENT 2021; 44:1885-1907. [PMID: 33608943 DOI: 10.1111/pce.14034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 06/12/2023]
Abstract
Nitrogen sources are all converted into ammonium/ia as a first step of assimilation. It is reasonable to expect that molecular components involved in the transport of ammonium/ia across biological membranes connect with the regulation of both nitrogen and central metabolism. We applied both genetic (i.e., Δamt mutation) and environmental treatments to a target biological system, the cyanobacterium Anabaena sp PCC 7120. The aim was to both perturb nitrogen metabolism and induce multiple inner nitrogen states, respectively, followed by targeted quantification of key proteins, metabolites and enzyme activities. The absence of AMT transporters triggered a substantial whole-system response, affecting enzyme activities and quantity of proteins and metabolites, spanning nitrogen and carbon metabolisms. Moreover, the Δamt strain displayed a molecular fingerprint indicating nitrogen deficiency even under nitrogen replete conditions. Contrasting with such dynamic adaptations was the striking near-complete lack of an externally measurable altered phenotype. We conclude that this species evolved a highly robust and adaptable molecular network to maintain homeostasis, resulting in substantial internal but minimal external perturbations. This analysis provides evidence for a potential role of AMT transporters in the regulatory/signalling network of nitrogen metabolism and the existence of a novel fourth regulatory mechanism controlling glutamine synthetase activity.
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Affiliation(s)
- Giorgio Perin
- Department of Life Sciences, Imperial College London, London, UK
| | - Tyler Fletcher
- Complex Carbohydrate Research Center and Department of Chemistry, University of Georgia, Athens, Georgia, USA
| | - Virag Sagi-Kiss
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - David C A Gaboriau
- Facility for Imaging by Light Microscopy, NHLI, Imperial College London, London, UK
| | - Mathew R Carey
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Jacob G Bundy
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Patrik R Jones
- Department of Life Sciences, Imperial College London, London, UK
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10
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Schätzle H, Brouwer EM, Liebhart E, Stevanovic M, Schleiff E. Comparative Phenotypic Analysis of Anabaena sp. PCC 7120 Mutants of Porinlike Genes. J Microbiol Biotechnol 2021; 31:645-658. [PMID: 33879642 PMCID: PMC9705863 DOI: 10.4014/jmb.2103.03009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/05/2021] [Accepted: 04/06/2021] [Indexed: 12/15/2022]
Abstract
Porins are essential for the viability of Gram-negative bacteria. They ensure the uptake of nutrients, can be involved in the maintenance of outer membrane integrity and define the antibiotic or drug resistance of organisms. The function and structure of porins in proteobacteria is well described, while their function in photoautotrophic cyanobacteria has not been systematically explored. We compared the domain architecture of nine putative porins in the filamentous cyanobacterium Anabaena sp. PCC 7120 and analyzed the seven candidates with predicted OprB-domain. Single recombinant mutants of the seven genes were created and their growth capacity under different conditions was analyzed. Most of the putative porins seem to be involved in the transport of salt and copper, as respective mutants were resistant to elevated concentrations of these substances. In turn, only the mutant of alr2231 was less sensitive to elevated zinc concentrations, while mutants of alr0834, alr4741 and all4499 were resistant to high manganese concentrations. Notably the mutant of alr4550 shows a high sensitivity against harmful compounds, which is indicative for a function related to the maintenance of outer membrane integrity. Moreover, the mutant of all5191 exhibited a phenotype which suggests either a higher nitrate demand or an inefficient nitrogen fixation. The dependency of porin membrane insertion on Omp85 proteins was tested exemplarily for Alr4550, and an enhanced aggregation of Alr4550 was observed in two omp85 mutants. The comparative analysis of porin mutants suggests that the proteins in parts perform distinct functions related to envelope integrity and solute uptake.
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Affiliation(s)
- Hannah Schätzle
- Institute for Molecular Biosciences, Goethe University, Frankfurt am Main, Germany,FIERCE, Goethe University, Frankfurt am Main, Germany,Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt am Main, Germany
| | - Eva-Maria Brouwer
- Institute for Molecular Biosciences, Goethe University, Frankfurt am Main, Germany
| | - Elisa Liebhart
- Institute for Molecular Biosciences, Goethe University, Frankfurt am Main, Germany
| | - Mara Stevanovic
- Institute for Molecular Biosciences, Goethe University, Frankfurt am Main, Germany
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Goethe University, Frankfurt am Main, Germany,FIERCE, Goethe University, Frankfurt am Main, Germany,Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt am Main, Germany,Frankfurt Institute of Advanced Studies, Frankfurt am Main, Germany,Corresponding author Phone: +49 69 798 29287 Fax: +49 69 798 29286 E-mail:
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11
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Bauer A, Forchhammer K. Bacterial Predation on Cyanobacteria. Microb Physiol 2021; 31:99-108. [PMID: 34010833 DOI: 10.1159/000516427] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/07/2021] [Indexed: 11/19/2022]
Abstract
Predatory bacteria gained interest in the last 20 years. Nevertheless, only a few species are well characterized. The endobiotic predator Bdellovibrio bacteriovorus invades its prey to consume it from the inside, whereas Myxococcus xanthus hunts as a whole group to overcome its prey. Both species were described to prey on cyanobacteria as well. This minireview summarizes the findings of the last 20 years of predatory bacteria of cyanobacteria and is supplemented by new findings from a screening experiment for bacterial predators of the model organism Anabaena variabilis PCC 7937. Known predatory bacteria of cyanobacteria belong to the phyla Proteobacteria, Bacteroidetes, and Firmicutes and follow different hunting strategies. The underlying mechanisms are in most cases not known in much detail. Isolates from the screening experiment were clustered after predation behaviour and analyzed with respect to their size. The effect of predation in high nitrate levels and the occurrence of nitrogen-fixing cells, called heterocysts, are addressed.
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Affiliation(s)
- Antje Bauer
- Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls Universität, Tübingen, Germany
| | - Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls Universität, Tübingen, Germany
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12
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Garg R, Maldener I. The Dual Role of the Glycolipid Envelope in Different Cell Types of the Multicellular Cyanobacterium Anabaena variabilis ATCC 29413. Front Microbiol 2021; 12:645028. [PMID: 33897656 PMCID: PMC8064123 DOI: 10.3389/fmicb.2021.645028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/15/2021] [Indexed: 11/13/2022] Open
Abstract
Anabaena variabilis is a filamentous cyanobacterium that is capable to differentiate specialized cells, the heterocysts and akinetes, to survive under different stress conditions. Under nitrogen limited condition, heterocysts provide the filament with nitrogen by fixing N2. Akinetes are spore-like dormant cells that allow survival during adverse environmental conditions. Both cell types are characterized by the presence of a thick multilayered envelope, including a glycolipid layer. While in the heterocyst this glycolipid layer is required for the maintenance of a microoxic environment and nitrogen fixation, its function in akinetes is completely unknown. Therefore, we constructed a mutant deficient in glycolipid synthesis and investigated the performance of heterocysts and akinetes in that mutant strain. We chose to delete the gene Ava_2595, which is homolog to the known hglB gene, encoding a putative polyketide synthase previously shown to be involved in heterocyst glycolipid synthesis in Anabaena sp. PCC 7120, a species which does not form akinetes. Under the respective conditions, the Ava_2595 null mutant strain formed aberrant heterocysts and akinete-like cells, in which the specific glycolipid layers were absent. This confirmed firstly that both cell types use a glycolipid of identical chemical composition in their special envelopes and, secondly, that HglB is essential for glycolipid synthesis in both types of differentiated cells. As a consequence, the mutant was not able to fix N2 and to grow under diazotrophic conditions. Furthermore, the akinetes lacking the glycolipids showed a severely reduced tolerance to stress conditions, but could germinate normally under standard conditions. This demonstrates the importance of the glycolipid layer for the ability of akinetes as spore-like dormant cells to withstand freezing, desiccation, oxidative stress and attack by lytic enzymes. Our study established the dual role of the glycolipid layer in fulfilling different functions in the evolutionary-related specialized cells of cyanobacteria. It also indicates the existence of a common pathway involving HglB for the synthesis of glycolipids in heterocysts and akinetes.
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Affiliation(s)
- Ritu Garg
- Institute of Microbiology and Infection Medicine, Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Iris Maldener
- Institute of Microbiology and Infection Medicine, Organismic Interactions, University of Tübingen, Tübingen, Germany
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13
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Gao Y, Zhou X, Zhang MM, Liu YJ, Guo XP, Lei CR, Li WJ, Lu D. Response characteristics of the membrane integrity and physiological activities of the mutant strain Y217 under exogenous butanol stress. Appl Microbiol Biotechnol 2021; 105:2455-2472. [PMID: 33606076 DOI: 10.1007/s00253-021-11174-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/30/2021] [Accepted: 02/10/2021] [Indexed: 01/05/2023]
Abstract
Butanol inhibits bacterial activity by destroying the cell membrane of Clostridium acetobutylicum strains and altering functionality. Butanol toxicity also results in destruction of the phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS), thereby preventing glucose transport and phosphorylation and inhibiting transmembrane transport and assimilation of sugars, amino acids, and other nutrients. In this study, based on the addition of exogenous butanol, the tangible macro indicators of changes in the carbon ion beam irradiation-mutant Y217 morphology were observed using scanning electron microscopy (SEM). The mutant has lower microbial adhesion to hydrocarbon (MATH) value than C. acetobutylicum ATCC 824 strain. FDA fluorescence intensity and conductivity studies demonstrated the intrinsically low membrane permeability of the mutant membrane, with membrane potential remaining relatively stable. Monounsaturated FAs (MUFAs) accounted for 35.17% of the mutant membrane, and the saturated fatty acids (SFA)/unsaturated fatty acids (UFA) ratio in the mutant cell membrane was 1.65. In addition, we conducted DNA-level analysis of the mutant strain Y217. Expectedly, through screening, we found gene mutant sites encoding membrane-related functions in the mutant, including ATP-binding cassette (ABC) transporter-related genes, predicted membrane proteins, and the PTS transport system. It is noteworthy that an unreported predicted membrane protein (CAC 3309) may be related to changes in mutant cell membrane properties. KEY POINTS: • Mutant Y217 exhibited better membrane integrity and permeability. • Mutant Y217 was more resistant to butanol toxicity. • Some membrane-related genes of mutant Y217 were mutated.
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Affiliation(s)
- Yue Gao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100049, China
| | - Xiang Zhou
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100049, China
| | - Miao-Miao Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100049, China.,Gansu Key Laboratory of Microbial Resources Exploitation and Application, Lanzhou, 730070, China
| | - Ya-Jun Liu
- University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100049, China.,Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Xiao-Peng Guo
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China
| | - Cai-Rong Lei
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100049, China
| | - Wen-Jian Li
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100049, China.,Gansu Key Laboratory of Microbial Resources Exploitation and Application, Lanzhou, 730070, China
| | - Dong Lu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China. .,University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100049, China. .,Gansu Key Laboratory of Microbial Resources Exploitation and Application, Lanzhou, 730070, China.
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14
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The Two TpsB-Like Proteins in Anabaena sp. Strain PCC 7120 Are Involved in Secretion of Selected Substrates. J Bacteriol 2021; 203:JB.00568-20. [PMID: 33257527 DOI: 10.1128/jb.00568-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 11/23/2020] [Indexed: 11/20/2022] Open
Abstract
The outer membrane of Gram-negative bacteria acts as an initial diffusion barrier that shields the cell from the environment. It contains many membrane-embedded proteins required for functionality of this system. These proteins serve as solute and lipid transporters or as machines for membrane insertion or secretion of proteins. The genome of Anabaena sp. strain PCC 7120 codes for two outer membrane transporters termed TpsB1 and TpsB2. They belong to the family of the two-partner secretion system proteins which are characteristic of pathogenic bacteria. Because pathogenicity of Anabaena sp. strain PCC 7120 has not been reported, the function of these two cyanobacterial TpsB proteins was analyzed. TpsB1 is encoded by alr1659, while TpsB2 is encoded by all5116 The latter is part of a genomic region containing 11 genes encoding TpsA-like proteins. However, tpsB2 is transcribed independently of a tpsA gene cluster. Bioinformatics analysis revealed the presence of at least 22 genes in Anabaena sp. strain PCC 7120 putatively coding for substrates of the TpsB system, suggesting a rather global function of the two TpsB proteins. Insertion of a plasmid into each of the two genes resulted in altered outer membrane integrity and antibiotic resistance. In addition, the expression of genes coding for the Clp and Deg proteases is dysregulated in these mutants. Moreover, for two of the putative substrates, a dependence of the secretion on functional TpsB proteins could be confirmed. We confirm the existence of a two-partner secretion system in Anabaena sp. strain PCC 7120 and predict a large pool of putative substrates.IMPORTANCE Cyanobacteria are important organisms for the ecosystem, considering their contribution to carbon fixation and oxygen production, while at the same time some species produce compounds that are toxic to their environment. As a consequence, cyanobacterial overpopulation might negatively impact the diversity of natural communities. Thus, a detailed understanding of cyanobacterial interaction with the environment, including other organisms, is required to define their impact on ecosystems. While two-partner secretion systems in pathogenic bacteria are well known, we provide a first description of the cyanobacterial two-partner secretion system.
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15
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Inomura K, Deutsch C, Masuda T, Prášil O, Follows MJ. Quantitative models of nitrogen-fixing organisms. Comput Struct Biotechnol J 2020; 18:3905-3924. [PMID: 33335688 PMCID: PMC7733014 DOI: 10.1016/j.csbj.2020.11.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 10/26/2022] Open
Abstract
Nitrogen-fixing organisms are of importance to the environment, providing bioavailable nitrogen to the biosphere. Quantitative models have been used to complement the laboratory experiments and in situ measurements, where such evaluations are difficult or costly. Here, we review the current state of the quantitative modeling of nitrogen-fixing organisms and ways to enhance the bridge between theoretical and empirical studies.
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Affiliation(s)
- Keisuke Inomura
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Curtis Deutsch
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Takako Masuda
- Institute of Microbiology, The Czech Academy of Sciences, Opatovický mlýn, Třeboň, Czech Republic
| | - Ondřej Prášil
- Institute of Microbiology, The Czech Academy of Sciences, Opatovický mlýn, Třeboň, Czech Republic
| | - Michael J. Follows
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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16
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Real-time monitoring of the in vivo redox state transition using the ratiometric redox state sensor protein FROG/B. Proc Natl Acad Sci U S A 2020; 117:16019-16026. [PMID: 32576684 DOI: 10.1073/pnas.1918919117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The intracellular redox state is one of the key factors regulating various physiological phenomena in the cell. Monitoring this state is therefore important for understanding physiological homeostasis in cells. Various fluorescent sensor proteins have already been developed to monitor intracellular redox state. We also developed fluorescent redox sensor proteins named Oba-Q and Re-Q, the emissions of which are quenched under oxidized and reduced conditions, respectively. Although these sensors were useful to visualize the redox changes in the cell over time, they have the weakness that their emission signals are directly influenced by their in situ expression levels. To overcome this problem, we developed a redox sensor protein with a single excitation peak and dual variable emission peaks. This sensor protein shows green emission under oxidized conditions and blue emission under reduced conditions. We therefore named this sensor FROG/B, fluorescent protein with redox-dependent change in green/blue. By using this sensor, we successfully measured the changes in intracellular redox potentials in cyanobacterial cells quantitatively caused by light/dark transition just by calculating the ratio of emission between green and blue signals.
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17
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Nieves-Morión M, Flores E, Foster RA. Predicting substrate exchange in marine diatom-heterocystous cyanobacteria symbioses. Environ Microbiol 2020; 22:2027-2052. [PMID: 32281201 DOI: 10.1111/1462-2920.15013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 11/27/2022]
Abstract
In the open ocean, some phytoplankton establish symbiosis with cyanobacteria. Some partnerships involve diatoms as hosts and heterocystous cyanobacteria as symbionts. Heterocysts are specialized cells for nitrogen fixation, and a function of the symbiotic cyanobacteria is to provide the host with nitrogen. However, both partners are photosynthetic and capable of carbon fixation, and the possible metabolites exchanged and mechanisms of transfer are poorly understood. The symbiont cellular location varies from internal to partial to fully external, and this is reflected in the symbiont genome size and content. In order to identify the membrane transporters potentially involved in metabolite exchange, we compare the draft genomes of three differently located symbionts with known transporters mainly from model free-living heterocystous cyanobacteria. The types and numbers of transporters are directly related to the symbiont cellular location: restricted in the endosymbionts and wider in the external symbiont. Three proposed models of metabolite exchange are suggested which take into account the type of transporters in the symbionts and the influence of their cellular location on the available nutrient pools. These models provide a basis for several hypotheses that given the importance of these symbioses in global N and C budgets, warrant future testing.
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Affiliation(s)
- Mercedes Nieves-Morión
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, Seville, E-41092, Spain
| | - Rachel A Foster
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
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18
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Mihara S, Sugiura K, Yoshida K, Hisabori T. Thioredoxin targets are regulated in heterocysts of cyanobacterium Anabaena sp. PCC 7120 in a light-independent manner. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2018-2027. [PMID: 31863668 PMCID: PMC7242069 DOI: 10.1093/jxb/erz561] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 12/18/2019] [Indexed: 05/22/2023]
Abstract
In the nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120, glucose 6-phosphate dehydrogenase (G6PDH) plays an important role in producing the power for reducing nitrogenase under light conditions. Our previous study showed that thioredoxin suppresses G6PDH by reducing its activator protein OpcA, implying that G6PDH is inactivated under light conditions because thioredoxins are reduced by the photosynthetic electron transport system in cyanobacteria. To address how Anabaena sp. PCC 7120 maintains G6PDH activity even under light conditions when nitrogen fixation occurs, we investigated the redox regulation system in vegetative cells and specific nitrogen-fixing cells named heterocysts, individually. We found that thioredoxin target proteins were more oxidized in heterocysts than in vegetative cells under light conditions. Alterations in the redox regulation mechanism of heterocysts may affect the redox states of thioredoxin target proteins, including OpcA, so that G6PDH is activated in heterocysts even under light conditions.
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Affiliation(s)
- Shoko Mihara
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Kazunori Sugiura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- Present address: The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Keisuke Yoshida
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- Correspondence:
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19
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The Integrity of the Cell Wall and Its Remodeling during Heterocyst Differentiation Are Regulated by Phylogenetically Conserved Small RNA Yfr1 in Nostoc sp. Strain PCC 7120. mBio 2020; 11:mBio.02599-19. [PMID: 31964726 PMCID: PMC6974561 DOI: 10.1128/mbio.02599-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Bacterial small RNAs (sRNAs) are important players affecting the regulation of essentially every aspect of bacterial physiology. The cell wall is a highly dynamic structure that protects bacteria from their fluctuating environment. Cell envelope remodeling is particularly critical for bacteria that undergo differentiation processes, such as spore formation or differentiation of heterocysts. Heterocyst development involves the deposition of additional layers of glycolipids and polysaccharides outside the outer membrane. Here, we show that a cyanobacterial phylogenetically conserved small regulatory RNA, Yfr1, coordinates the expression of proteins involved in cell wall-related processes, including peptidoglycan metabolism and transport of different molecules, as well as expression of several proteins involved in heterocyst differentiation. Yfr1 is a strictly conserved small RNA in cyanobacteria. A bioinformatic prediction to identify possible interactions of Yfr1 with mRNAs was carried out by using the sequences of Yfr1 from several heterocyst-forming strains, including Nostoc sp. strain PCC 7120. The results of the prediction were enriched in genes encoding outer membrane proteins and enzymes related to peptidoglycan biosynthesis and turnover. Heterologous expression assays with Escherichia coli demonstrated direct interactions of Yfr1 with mRNAs of 11 of the candidate genes. The expression of 10 of them (alr2458, alr4550, murC, all4829, all2158, mraY, alr2269, alr0834, conR, patN) was repressed by interaction with Yfr1, whereas the expression of amiC2, encoding an amidase, was increased. The interactions between Yfr1 and the 11 mRNAs were confirmed by site-directed mutagenesis of Yfr1. Furthermore, a Nostoc strain with reduced levels of Yfr1 had larger amounts of mraY and murC mRNAs, supporting a role for Yfr1 in the regulation of those genes. Nostoc strains with either reduced or increased expression of Yfr1 showed anomalies in cell wall completion and were more sensitive to vancomycin than the wild-type strain. Furthermore, growth in the absence of combined nitrogen, which involves the differentiation of heterocysts, was compromised in the strain overexpressing Yfr1, and filaments were broken at the connections between vegetative cells and heterocysts. These results indicate that Yfr1 is an important regulator of cell wall homeostasis and correct cell wall remodeling during heterocyst differentiation.
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20
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Kourpa K, Manarolaki E, Lyratzakis A, Strataki V, Rupprecht F, Langer JD, Tsiotis G. Proteome Analysis of Enriched Heterocysts from Two Hydrogenase Mutants fromAnabaenasp. PCC 7120. Proteomics 2019; 19:e1800332. [DOI: 10.1002/pmic.201800332] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 07/12/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Katerina Kourpa
- Division of BiochemistryDepartment of ChemistryUniversity of Crete P.O. Box 2208, GR‐71003 Voutes Greece
| | - Eftychia Manarolaki
- Division of BiochemistryDepartment of ChemistryUniversity of Crete P.O. Box 2208, GR‐71003 Voutes Greece
| | - Alexandros Lyratzakis
- Division of BiochemistryDepartment of ChemistryUniversity of Crete P.O. Box 2208, GR‐71003 Voutes Greece
| | - Vasso Strataki
- Division of BiochemistryDepartment of ChemistryUniversity of Crete P.O. Box 2208, GR‐71003 Voutes Greece
| | - Fiona Rupprecht
- Max Planck Institute for Brain Research Max‐von‐Laue‐Straße 4 D‐60438 Frankfurt am Main Germany
| | - Julian D. Langer
- Max Planck Institute for Brain Research Max‐von‐Laue‐Straße 4 D‐60438 Frankfurt am Main Germany
- Max Planck Institute for Biophysics Max‐von‐Laue‐Straße 3 D‐60438 Frankfurt am Main Germany
| | - Georgios Tsiotis
- Division of BiochemistryDepartment of ChemistryUniversity of Crete P.O. Box 2208, GR‐71003 Voutes Greece
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21
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Roles of DevBCA-like ABC transporters in the physiology of Anabaena sp. PCC 7120. Int J Med Microbiol 2019; 309:325-330. [DOI: 10.1016/j.ijmm.2019.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/10/2019] [Accepted: 04/26/2019] [Indexed: 01/19/2023] Open
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22
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Brouwer E, Ngo G, Yadav S, Ladig R, Schleiff E. Tic22 from
Anabaena
sp. PCC 7120 with holdase function involved in outer membrane protein biogenesis shuttles between plasma membrane and Omp85. Mol Microbiol 2019; 111:1302-1316. [DOI: 10.1111/mmi.14222] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Eva‐Maria Brouwer
- Institute for Molecular Biosciences Goethe University Frankfurt am Main Frankfurt am Main Germany
| | - Giang Ngo
- Institute for Molecular Biosciences Goethe University Frankfurt am Main Frankfurt am Main Germany
| | - Shivam Yadav
- Institute for Molecular Biosciences Goethe University Frankfurt am Main Frankfurt am Main Germany
- Centre of Advanced Studies in Botany, Institute of Science Banaras Hindu University Varanasi India
| | - Roman Ladig
- Institute for Molecular Biosciences Goethe University Frankfurt am Main Frankfurt am Main Germany
| | - Enrico Schleiff
- Institute for Molecular Biosciences Goethe University Frankfurt am Main Frankfurt am Main Germany
- Buchman Institute for Molecular Life Sciences Goethe University Frankfurt am Main Frankfurt am Main Germany
- Frankfurt Institute of Advanced Studies Frankfurt am Main Germany
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23
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Shvarev D, Nishi CN, Maldener I. Glycolipid composition of the heterocyst envelope of Anabaena sp. PCC 7120 is crucial for diazotrophic growth and relies on the UDP-galactose 4-epimerase HgdA. Microbiologyopen 2019; 8:e00811. [PMID: 30803160 PMCID: PMC6692557 DOI: 10.1002/mbo3.811] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 01/05/2023] Open
Abstract
The nitrogenase complex in the heterocysts of the filamentous freshwater cyanobacterium Anabaenasp. PCC 7120 fixes atmospheric nitrogen to allow diazotrophic growth. The heterocyst cell envelope protects the nitrogenase from oxygen and consists of a polysaccharide and a glycolipid layer that are formed by a complex process involving the recruitment of different proteins. Here, we studied the function of the putative nucleoside‐diphosphate‐sugar epimerase HgdA, which along with HgdB and HgdC is essential for deposition of the glycolipid layer and growth without a combined nitrogen source. Using site‐directed mutagenesis and single homologous recombination approach, we performed a thoroughly functional characterization of HgdA and confirmed that the glycolipid layer of the hgdAmutant heterocyst is aberrant as shown by transmission electron microscopy and chemical analysis. The hgdA gene was expressed during late stages of the heterocyst differentiation. GFP‐tagged HgdA protein localized inside the heterocysts. The purified HgdA protein had UDP‐galactose 4‐epimerase activity in vitro. This enzyme could be responsible for synthesis of heterocyst‐specific glycolipid precursors, which could be transported over the cell wall by the ABC transporter components HgdB/HgdC.
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Affiliation(s)
- Dmitry Shvarev
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Carolina N Nishi
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Iris Maldener
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of Tübingen, Tübingen, Germany
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24
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Qiu Y, Tian S, Gu L, Hildreth M, Zhou R. Identification of surface polysaccharides in akinetes, heterocysts and vegetative cells of Anabaena cylindrica using fluorescein-labeled lectins. Arch Microbiol 2018; 201:17-25. [PMID: 30173343 DOI: 10.1007/s00203-018-1565-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/10/2018] [Accepted: 08/22/2018] [Indexed: 11/26/2022]
Abstract
In response to environmental changes, Anabaena cylindrica differentiate three cell types: vegetative cells for photosynthesis, heterocysts for nitrogen fixation, and akinetes for stress survival. Cell-surface polysaccharides play important roles in cyanobacterial ecophysiology. In this study, specific cell-surface sugars were discovered in heterocysts, akinetes and vegetative cells of A. cylindrica using 20 fluorescein-labeled lectins. Both N-acetylglucosamine-binding lectins WGA and succinylated WGA bound specifically to the vegetative cells. Akinetes bound to three mannose-binding lectins (LCA, PSA, and ConA), and one of the galactose-binding lectins (GSL-I). Heterocyst also bound to ConA. However, the heterocysts in all4388 mutant of Anabaena sp. PCC 7120, in which the putative polysaccharide export protein gene all4388 was disrupted, exhibited diminished binding to ConA. Identification of distinct cell-surface sugar helped us to understand the role of polysaccharide for each cell type. Fluorescence-activated cell sorting may be applicable in isolating each cell type for comparative "omics" studies among the three cell types.
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Affiliation(s)
- Yeyan Qiu
- Department of Biology and Microbiology, South Dakota State University, Brookings, USA
| | - Shengni Tian
- College of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Liping Gu
- Department of Biology and Microbiology, South Dakota State University, Brookings, USA
| | - Michael Hildreth
- Department of Biology and Microbiology, South Dakota State University, Brookings, USA
| | - Ruanbao Zhou
- Department of Biology and Microbiology, South Dakota State University, Brookings, USA.
- BioSNTR, South Dakota State University, Brookings, SD, USA.
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25
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Driscoll CB, Meyer KA, Šulčius S, Brown NM, Dick GJ, Cao H, Gasiūnas G, Timinskas A, Yin Y, Landry ZC, Otten TG, Davis TW, Watson SB, Dreher TW. A closely-related clade of globally distributed bloom-forming cyanobacteria within the Nostocales. HARMFUL ALGAE 2018; 77:93-107. [PMID: 30005805 DOI: 10.1016/j.hal.2018.05.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/18/2018] [Accepted: 05/24/2018] [Indexed: 06/08/2023]
Abstract
In order to better understand the relationships among current Nostocales cyanobacterial blooms, eight genomes were sequenced from cultured isolates or from environmental metagenomes of recent planktonic Nostocales blooms. Phylogenomic analysis of publicly available sequences placed the new genomes among a group of 15 genomes from four continents in a distinct ADA clade (Anabaena/Dolichospermum/Aphanizomenon) within the Nostocales. This clade contains four species-level groups, two of which include members with both Anabaena-like and Aphanizomenon flos-aquae-like morphology. The genomes contain many repetitive genetic elements and a sizable pangenome, in which ABC-type transporters are highly represented. Alongside common core genes for photosynthesis, the differentiation of N2-fixing heterocysts, and the uptake and incorporation of the major nutrients P, N and S, we identified several gene pathways in the pangenome that may contribute to niche partitioning. Genes for problematic secondary metabolites-cyanotoxins and taste-and-odor compounds-were sporadically present, as were other polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) gene clusters. By contrast, genes predicted to encode the ribosomally generated bacteriocin peptides were found in all genomes.
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Affiliation(s)
- Connor B Driscoll
- Department of Microbiology, Oregon State University, 226 Nash Hall, Corvallis, OR, 97331, USA
| | - Kevin A Meyer
- Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005, USA; Cooperative Institute for Great Lakes Research (CIGLR), University of Michigan, Ann Arbor, MI 48109-1005, USA
| | - Sigitas Šulčius
- Laboratory of Algology and Microbial Ecology, Akademijos Str. 2, LT-08412, Vilnius, Lithuania
| | - Nathan M Brown
- Department of Microbiology, Oregon State University, 226 Nash Hall, Corvallis, OR, 97331, USA
| | - Gregory J Dick
- Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005, USA
| | - Huansheng Cao
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, 427 E Tyler Mall, Tempe, AZ 85287, USA
| | - Giedrius Gasiūnas
- Department of Protein-DNA Interactions, Institute of Biotechnology, Vilnius University, Saulėtekio av. 7, LT-10257, Vilnius, Lithuania
| | - Albertas Timinskas
- Department of Bioinformatics, Institute of Biotechnology, Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania
| | - Yanbin Yin
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL, USA
| | - Zachary C Landry
- Department of Microbiology, Oregon State University, 226 Nash Hall, Corvallis, OR, 97331, USA
| | - Timothy G Otten
- Department of Microbiology, Oregon State University, 226 Nash Hall, Corvallis, OR, 97331, USA
| | - Timothy W Davis
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43402, USA
| | - Susan B Watson
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, ON L7S 1A1, Canada
| | - Theo W Dreher
- Department of Microbiology, Oregon State University, 226 Nash Hall, Corvallis, OR, 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA.
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26
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Zhang JY, Lin GM, Xing WY, Zhang CC. Diversity of Growth Patterns Probed in Live Cyanobacterial Cells Using a Fluorescent Analog of a Peptidoglycan Precursor. Front Microbiol 2018; 9:791. [PMID: 29740419 PMCID: PMC5928242 DOI: 10.3389/fmicb.2018.00791] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/09/2018] [Indexed: 01/07/2023] Open
Abstract
Cyanobacteria were the first oxygenic photosynthetic organisms during evolution and were ancestors of plastids. Cyanobacterial cells exhibit an extraordinary diversity in their size and shape, and bacterial cell morphology largely depends on the synthesis and the dynamics of the peptidoglycan (PG) layer. Here, we used a fluorescence analog of the PG synthesis precursor D-Ala, 7-Hydroxycoumarin-amino-D-alanine (HADA), to probe the PG synthesis pattern in live cells of cyanobacteria with different morphology. They displayed diverse synthesis patterns, with some strains showing an intensive HADA incorporation at the septal region, whereas others gave an HADA signal distributed around the cells. Growth zones covering several cells at the tips of the filament were present in some filamentous strains such as in Arthrospira. In Anabaena PCC 7120, which is capable of differentiating heterocysts for N2 fixation, PG synthesis followed the cell division cycle. In addition, an HADA incorporation was strongly activated from 12 to 15 h following the initiation of heterocyst development, indicating a thickening of the PG layer in heterocysts. The PG synthesis pattern is diverse in cyanobacteria and responds to developmental regulation. The use of fluorescent analogs may serve as a useful tool for understanding the mechanisms of cell growth and morphogenesis operating in these organisms.
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Affiliation(s)
- Ju-Yuan Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Gui-Ming Lin
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Wei-Yue Xing
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Cheng-Cai Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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Thioredoxin regulates G6PDH activity by changing redox states of OpcA in the nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120. Biochem J 2018; 475:1091-1105. [DOI: 10.1042/bcj20170869] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/31/2018] [Accepted: 02/13/2018] [Indexed: 01/03/2023]
Abstract
Glucose 6-phosphate dehydrogenase (G6PDH) catalyzes the first reaction in the oxidative pentose phosphate pathway. In green plant chloroplasts, G6PDH is a unique redox-regulated enzyme, since it is inactivated under the reducing conditions. This regulation is accomplished using a redox-active cysteine pair, which is conserved in plant G6PDH. The inactivation of this enzyme under conditions of light must be beneficial to prevent release of CO2 from the photosynthetic carbon fixation cycle. In the filamentous, heterocyst-forming, nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 (Anabaena 7120), G6PDH plays a pivotal role in providing reducing power for nitrogenase, and its activity is also reported to be suppressed by reduction, though Anabaena G6PDH does not conserve the critical cysteines for regulation. Based on the thorough analyses of the redox regulation mechanisms of G6PDH from Anabaena 7120 and its activator protein OpcA, we found that m-type thioredoxin regulates G6PDH activity by changing the redox states of OpcA. Mass spectrometric analysis and mutagenesis studies indicate that Cys393 and Cys399 of OpcA are responsible for the redox regulation property of this protein. Moreover, in vivo analyses of the redox states of OpcA showed that more than half of the OpcA is present as an oxidized form, even under conditions of light, when cells are cultured under the nitrogen-fixing conditions. This redox regulation of OpcA might be necessary to provide reducing power for nitrogenase by G6PDH in heterocysts even during the day.
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Nieves-Morión M, Flores E. Multiple ABC glucoside transporters mediate sugar-stimulated growth in the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:40-48. [PMID: 29159995 DOI: 10.1111/1758-2229.12603] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
Cyanobacteria are generally capable of photoautotrophic growth and are widely distributed on Earth. The model filamentous, heterocyst-forming strain Anabaena sp. PCC 7120 has long been considered as a strict photoautotroph but is now known to be able to assimilate fructose. We have previously described two components of ABC glucoside uptake transporters from Anabaena that are involved in uptake of the sucrose analog esculin: GlsC [a nucleotide-binding domain subunit (NBD)] and GlsP [a transmembrane component (TMD)]. Here, we created Anabaena mutants of genes encoding three further ABC transporter components needed for esculin uptake: GlsD (NBD), GlsQ (TMD) and GlsR (periplasmic substrate-binding protein). Phototrophic growth of Anabaena was significantly stimulated by sucrose, fructose and glucose. Whereas the glsC and glsD mutants were drastically hampered in sucrose-stimulated growth, the different gls mutants were generally impaired in sugar-dependent growth. Our results suggest the participation of Gls and other ABC transporters encoded in the Anabaena genome in sugar-stimulated growth. Additionally, Gls transporter components influence the function of septal junctions in the Anabaena filament. We suggest that mixotrophic growth is important in cyanobacterial physiology and may be relevant for the wide success of these organisms in diverse environments.
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Affiliation(s)
- Mercedes Nieves-Morión
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, 41092, Seville, Spain
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, 41092, Seville, Spain
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Khetkorn W, Rastogi RP, Incharoensakdi A, Lindblad P, Madamwar D, Pandey A, Larroche C. Microalgal hydrogen production - A review. BIORESOURCE TECHNOLOGY 2017; 243:1194-1206. [PMID: 28774676 DOI: 10.1016/j.biortech.2017.07.085] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/13/2017] [Accepted: 07/17/2017] [Indexed: 06/07/2023]
Abstract
Bio-hydrogen from microalgae including cyanobacteria has attracted commercial awareness due to its potential as an alternative, reliable and renewable energy source. Photosynthetic hydrogen production from microalgae can be interesting and promising options for clean energy. Advances in hydrogen-fuel-cell technology may attest an eco-friendly way of biofuel production, since, the use of H2 to generate electricity releases only water as a by-product. Progress in genetic/metabolic engineering may significantly enhance the photobiological hydrogen production from microalgae. Manipulation of competing metabolic pathways by modulating the certain key enzymes such as hydrogenase and nitrogenase may enhance the evolution of H2 from photoautotrophic cells. Moreover, biological H2 production at low operating costs is requisite for economic viability. Several photobioreactors have been developed for large-scale biomass and hydrogen production. This review highlights the recent technological progress, enzymes involved and genetic as well as metabolic engineering approaches towards sustainable hydrogen production from microalgae.
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Affiliation(s)
- Wanthanee Khetkorn
- Division of Biology, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Thanyaburi, Pathumthani 12110, Thailand
| | - Rajesh P Rastogi
- Ministry of Environment, Forest and Climate Change, Indira Paryavaran Bhawan, Jor Bagh Road, New Delhi 110 003, India.
| | - Aran Incharoensakdi
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Bangkok 10330, Thailand
| | - Peter Lindblad
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Datta Madamwar
- Department of Biosciences, UGC-Centre of Advanced Study, Sardar Patel University, Vadtal Road, Satellite Campus, Bakrol, Anand, Gujarat 388 315, India
| | - Ashok Pandey
- Center of Innovative and Applied Bioprocessing, C-127 2nd Floor Phase 8 Industrial Area, SAS Nagar, Mohali 160 071, Punjab, India
| | - Christian Larroche
- Labex IMobS3 and Institut Pascal, 4 Avenue Blaise Pascal, TSA 60026/CS 60026, 63178 Aubière Cedex, France
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Herrero A, Stavans J, Flores E. The multicellular nature of filamentous heterocyst-forming cyanobacteria. FEMS Microbiol Rev 2016; 40:831-854. [DOI: 10.1093/femsre/fuw029] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/10/2016] [Accepted: 07/09/2016] [Indexed: 11/13/2022] Open
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Singh S, Verma E, Tiwari B, N, Mishra AK. Modulation of fatty acids and hydrocarbons inAnabaena7120 and itsntcAmutant under calcium. J Basic Microbiol 2016; 57:171-183. [DOI: 10.1002/jobm.201600476] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 09/18/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Savita Singh
- Laboratory of Microbial Genetics, Department of Botany; Banaras Hindu University; Varanasi India
| | - Ekta Verma
- Laboratory of Microbial Genetics, Department of Botany; Banaras Hindu University; Varanasi India
| | - Balkrishna Tiwari
- Laboratory of Microbial Genetics, Department of Botany; Banaras Hindu University; Varanasi India
| | - Niveshika
- Laboratory of Microbial Genetics, Department of Botany; Banaras Hindu University; Varanasi India
| | - Arun Kumar Mishra
- Laboratory of Microbial Genetics, Department of Botany; Banaras Hindu University; Varanasi India
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Genomics of variation in nitrogen fixation activity in a population of the thermophilic cyanobacterium Mastigocladus laminosus. ISME JOURNAL 2016; 11:78-86. [PMID: 27505345 DOI: 10.1038/ismej.2016.105] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 06/07/2016] [Accepted: 06/14/2016] [Indexed: 01/07/2023]
Abstract
Variation in phenotypic traits that contribute to fitness influences a population's evolutionary response and its impact on ecosystem function following environmental change, yet its amount and nature are rarely known. Here, we investigated variation in nitrogen (N) fixation activity and its genetic basis for a random sample of laboratory strains of the cyanobacterium Mastigocladus laminosus from a N-limited, geothermally influenced stream in Yellowstone National Park. In a linear mixed-effects model, temperature and genetic differences among strains were the most important factors explaining variation in activity. Genome-wide analyses of genetic divergence between groups of strains that varied in N fixation activity revealed that few loci were strongly associated with these phenotypic differences. Notably, a single nonsynonymous polymorphism in the sulfate assimilation gene apsK explained >25% of the variation in activity at high temperature. We further identified a role for allelic variation of multiple terminal cytochrome oxidases for different aspects of N fixation. In addition, genomes of strains that fixed the most N overall contained a nonsense mutation in a histidine kinase gene that is expected to disrupt normal protein function and may result in transcriptional rewiring. This study illustrates how taking complementary approaches to link phenotype and genotype can inform our understanding of microbial population diversity.
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Mutation of the murC and murB Genes Impairs Heterocyst Differentiation in Anabaena sp. Strain PCC 7120. J Bacteriol 2016; 198:1196-206. [PMID: 26811320 DOI: 10.1128/jb.01027-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 01/20/2016] [Indexed: 01/04/2023] Open
Abstract
UNLABELLED To stabilize cellular integrity in the face of environmental perturbations, most bacteria, including cyanobacteria, synthesize and maintain a strong, flexible, three-dimensional peptidoglycan lattice. Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium capable of differentiating morphologically distinct nitrogen-fixing heterocyst cells in a periodic pattern. While heterocyst development has been shown to require proper peptidoglycan remodeling, the role of peptidoglycan synthesis has remained unclear. Here we report the identification of two peptidoglycan synthesis genes, murC (alr5065) and murB (alr5066), as required for heterocyst development. The murC and murB genes are predicted to encode a UDP-N-acetylmuramate:L-alanine ligase and a UDP-N-acetylenolpyruvoylglucosamine reductase, respectively, and we confirm enzymatic function through complementation of Escherichia coli strains deficient for these enzymes. Cells depleted of either murC or murB expression failed to differentiate heterocysts under normally inducing conditions and displayed decreased filament integrity. To identify the stage(s) of development affected by murC or murB depletion, the spatial distribution of expression of the patterning marker gene, patS, was examined. Whereas murB depletion did not affect the pattern of patS expression, murC depletion led to aberrant expression of patS in all cells of the filament. Finally, expression of gfp controlled by the region of DNA immediately upstream of murC was enriched in differentiating cells and was repressed by the transcription factor NtcA. Collectively, the data in this work provide evidence for a direct link between peptidoglycan synthesis and the maintenance of a biological pattern in a multicellular organism. IMPORTANCE Multicellular organisms that differentiate specialized cells must regulate morphological changes such that both cellular integrity and the dissemination of developmental signals are preserved. Here we show that the multicellular bacterium Anabaena, which differentiates a periodic pattern of specialized heterocyst cells, requires peptidoglycan synthesis by the murine ligase genes murC (alr5065) and murB (alr5066) for maintenance of patterned gene expression, filament integrity, and overall development. This work highlights the significant influence that intracellular structure and intercellular connections can have on the execution of a developmental program.
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D'Agostino PM, Song X, Neilan BA, Moffitt MC. Proteogenomics of a saxitoxin-producing and non-toxic strain ofAnabaena circinalis(cyanobacteria) in response to extracellular NaCl and phosphate depletion. Environ Microbiol 2016; 18:461-76. [DOI: 10.1111/1462-2920.13131] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 11/10/2015] [Accepted: 11/10/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Paul M. D'Agostino
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; NSW 2052 Australia
- School of Science and Health; Western Sydney University; Campbelltown NSW 2560 Australia
| | - Xiaomin Song
- Australian Proteomics Analysis Facility; Macquarie University; Macquarie Park NSW 2109 Australia
| | - Brett A. Neilan
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; NSW 2052 Australia
| | - Michelle C. Moffitt
- School of Science and Health; Western Sydney University; Campbelltown NSW 2560 Australia
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Wang XP, Jiang YL, Dai YN, Cheng W, Chen Y, Zhou CZ. Structural and enzymatic analyses of a glucosyltransferase Alr3699/HepE involved in Anabaena heterocyst envelop polysaccharide biosynthesis. Glycobiology 2015; 26:520-31. [PMID: 26692049 DOI: 10.1093/glycob/cwv167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 12/13/2015] [Indexed: 01/18/2023] Open
Abstract
Formation of the heterocyst envelope polysaccharide (HEP) is a key process for cyanobacterial heterocyst differentiation. The maturation of HEP in Anabaena sp. strain PCC 7120 is controlled by a gene cluster termed HEP island in addition to an operon alr3698-alr3699, which encodes two putative proteins termed Alr3698/HepD and Alr3699/HepE. Here we report the crystal structures of HepE in the apo-form and three complex forms that bind to UDP-glucose (UDPG), UDP&glucose, and UDP, respectively. The overall structure of HepE displays a typical GT-B fold of glycosyltransferases, comprising two separate β/α/β Rossmann-fold domains that form an inter-domain substrate-binding crevice. Structural analyses combined with enzymatic assays indicate that HepE is a glucosyltransferase using UDPG as a sugar donor. Further site-directed mutageneses enable us to assign the key residues that stabilize the sugar donor and putative acceptor. Based on the comparative structural analyses, we propose a putative catalytic cycle of HepE, which undergoes "open-closed-open" conformational changes upon binding to the substrates and release of products. These findings provide structural and catalytic insights into the first enzyme involved in the HEP biosynthesis pathway.
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Affiliation(s)
- Xue-Ping Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Yong-Liang Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Ya-Nan Dai
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Wang Cheng
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Yuxing Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Cong-Zhao Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
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Singh S, Mishra AK. Unraveling of cross talk between Ca(2+) and ROS regulating enzymes in Anabaena 7120 and ntcA mutant. J Basic Microbiol 2015; 56:762-78. [PMID: 26374944 DOI: 10.1002/jobm.201500326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/09/2015] [Indexed: 01/25/2023]
Abstract
In order to understand a cross talk between Ca(2+) and ROS regulating enzymes and the possible involvement of ntcA gene, Anabaena sp. PCC 7120 and its derivative ntcA mutant grown in varied levels of calcium chloride (0, 1, 10, and 100 mM) have been investigated. Scanning Electron Microscopy showed abnormal structure formation at high calcium concentration (100 mM) both in wild type and mutant. Fv /Fm values suggested that 100 mM calcium concentration was detrimental for photosynthetic apparatus. SOD, catalase, APX, GR, and peroxidase activity were found to be maximum for 100 mM and minimum for 1 mM of exogenously supplied calcium salt. NADPH contents were higher for wild type than mutant. RAPD-PCR and SDS-PAGE analysis revealed a difference in DNA as well as proteome pattern with changes in calcium chloride regime. Prominent bands of approximately 70, 33, 21, and 14 kDa expressed in the wild type served as the marker polypeptide bands under calcium supplementation. Results suggest that higher levels of calcium ion disturb the cellular homeostasis generating ROS, thereby inducing enhanced levels of antioxidative enzymes. Further, data also suggests possible involvement of ntcA gene in cross talk between calcium ion and ROS regulating enzymes.
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Affiliation(s)
- Savita Singh
- Department of Botany, Laboratory of Microbial Genetics, Banaras Hindu University, Varanasi, India
| | - Arun Kumar Mishra
- Department of Botany, Laboratory of Microbial Genetics, Banaras Hindu University, Varanasi, India
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Simm S, Keller M, Selymesi M, Schleiff E. The composition of the global and feature specific cyanobacterial core-genomes. Front Microbiol 2015; 6:219. [PMID: 25852675 PMCID: PMC4365693 DOI: 10.3389/fmicb.2015.00219] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 03/04/2015] [Indexed: 12/21/2022] Open
Abstract
Cyanobacteria are photosynthetic prokaryotes important for many ecosystems with a high potential for biotechnological usage e.g., in the production of bioactive molecules. Either asks for a deep understanding of the functionality of cyanobacteria and their interaction with the environment. This in part can be inferred from the analysis of their genomes or proteomes. Today, many cyanobacterial genomes have been sequenced and annotated. This information can be used to identify biological pathways present in all cyanobacteria as proteins involved in such processes are encoded by a so called core-genome. However, beside identification of fundamental processes, genes specific for certain cyanobacterial features can be identified by a holistic genome analysis as well. We identified 559 genes that define the core-genome of 58 analyzed cyanobacteria, as well as three genes likely to be signature genes for thermophilic and 57 genes likely to be signature genes for heterocyst-forming cyanobacteria. To get insights into cyanobacterial systems for the interaction with the environment we also inspected the diversity of the outer membrane proteome with focus on β-barrel proteins. We observed that most of the transporting outer membrane β-barrel proteins are not globally conserved in the cyanobacterial phylum. In turn, the occurrence of β-barrel proteins shows high strain specificity. The core set of outer membrane proteins globally conserved in cyanobacteria comprises three proteins only, namely the outer membrane β-barrel assembly protein Omp85, the lipid A transfer protein LptD, and an OprB-type porin. Thus, we conclude that cyanobacteria have developed individual strategies for the interaction with the environment, while other intracellular processes like the regulation of the protein homeostasis are globally conserved.
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Affiliation(s)
- Stefan Simm
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University Frankfurt am Main, Germany
| | - Mario Keller
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University Frankfurt am Main, Germany
| | - Mario Selymesi
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University Frankfurt am Main, Germany
| | - Enrico Schleiff
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University Frankfurt am Main, Germany ; Cluster of Excellence Frankfurt, Goethe University Frankfurt am Main, Germany ; Center of Membrane Proteomics, Goethe University Frankfurt am Main, Germany ; Buchmann Institute of Molecular Life Sciences, Goethe University Frankfurt am Main, Germany
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Sandh G, Ramström M, Stensjö K. Analysis of the early heterocyst Cys-proteome in the multicellular cyanobacterium Nostoc punctiforme reveals novel insights into the division of labor within diazotrophic filaments. BMC Genomics 2014; 15:1064. [PMID: 25476978 PMCID: PMC4363197 DOI: 10.1186/1471-2164-15-1064] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 11/12/2014] [Indexed: 01/30/2023] Open
Abstract
Background In the filamentous cyanobacterium Nostoc punctiforme ATCC 29133, removal of combined nitrogen induces the differentiation of heterocysts, a cell-type specialized in N2 fixation. The differentiation involves genomic, structural and metabolic adaptations. In cyanobacteria, changes in the availability of carbon and nitrogen have also been linked to redox regulated posttranslational modifications of protein bound thiol groups. We have here employed a thiol targeting strategy to relatively quantify the putative redox proteome in heterocysts as compared to N2-fixing filaments, 24 hours after combined nitrogen depletion. The aim of the study was to expand the coverage of the cell-type specific proteome and metabolic landscape of heterocysts. Results Here we report the first cell-type specific proteome of newly formed heterocysts, compared to N2-fixing filaments, using the cysteine-specific selective ICAT methodology. The data set defined a good quantitative accuracy of the ICAT reagent in complex protein samples. The relative abundance levels of 511 proteins were determined and 74% showed a cell-type specific differential abundance. The majority of the identified proteins have not previously been quantified at the cell-type specific level. We have in addition analyzed the cell-type specific differential abundance of a large section of proteins quantified in both newly formed and steady-state diazotrophic cultures in N. punctiforme. The results describe a wide distribution of members of the putative redox regulated Cys-proteome in the central metabolism of both vegetative cells and heterocysts of N. punctiforme. Conclusions The data set broadens our understanding of heterocysts and describes novel proteins involved in heterocyst physiology, including signaling and regulatory proteins as well as a large number of proteins with unknown function. Significant differences in cell-type specific abundance levels were present in the cell-type specific proteomes of newly formed diazotrophic filaments as compared to steady-state cultures. Therefore we conclude that by using our approach we are able to analyze a synchronized fraction of newly formed heterocysts, which enabled a better detection of proteins involved in the heterocyst specific physiology. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1064) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | - Karin Stensjö
- Microbial Chemistry, Department of Chemistry - Ångström Laboratory, Science for Life Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden.
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Cell envelope components influencing filament length in the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. J Bacteriol 2014; 196:4026-35. [PMID: 25201945 DOI: 10.1128/jb.02128-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Heterocyst-forming cyanobacteria grow as chains of cells (known as trichomes or filaments) that can be hundreds of cells long. The filament consists of individual cells surrounded by a cytoplasmic membrane and peptidoglycan layers. The cells, however, share a continuous outer membrane, and septal proteins, such as SepJ, are important for cell-cell contact and filament formation. Here, we addressed a possible role of cell envelope components in filamentation, the process of producing and maintaining filaments, in the model cyanobacterium Anabaena sp. strain PCC 7120. We studied filament length and the response of the filaments to mechanical fragmentation in a number of strains with mutations in genes encoding cell envelope components. Previously published peptidoglycan- and outer membrane-related gene mutants and strains with mutations in two genes (all5045 and alr0718) encoding class B penicillin-binding proteins isolated in this work were used. Our results show that filament length is affected in most cell envelope mutants, but the filaments of alr5045 and alr2270 gene mutants were particularly fragmented. All5045 is a dd-transpeptidase involved in peptidoglycan elongation during cell growth, and Alr2270 is an enzyme involved in the biosynthesis of lipid A, a key component of lipopolysaccharide. These results indicate that both components of the cell envelope, the murein sacculus and the outer membrane, influence filamentation. As deduced from the filament fragmentation phenotypes of their mutants, however, none of these elements is as important for filamentation as the septal protein SepJ.
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Golmakani MT, Mendiola J, Rezaei K, Ibáñez E. Pressurized limonene as an alternative bio-solvent for the extraction of lipids from marine microorganisms. J Supercrit Fluids 2014. [DOI: 10.1016/j.supflu.2014.05.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Hahn A, Stevanovic M, Brouwer E, Bublak D, Tripp J, Schorge T, Karas M, Schleiff E. Secretome analysis of Anabaena sp. PCC 7120 and the involvement of the TolC-homologue HgdD in protein secretion. Environ Microbiol 2014; 17:767-80. [PMID: 24890022 DOI: 10.1111/1462-2920.12516] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 05/18/2014] [Indexed: 12/01/2022]
Abstract
Secretion of proteins is a central strategy of bacteria to influence and respond to their environment. Until now, there has been very few discoveries regarding the cyanobacterial secrotome or the secretion machineries involved. For a mutant of the outer membrane channel TolC-homologue HgdD of Anabaena sp. PCC 7120, a filamentous and heterocyst-forming cyanobacterium, an altered secretome profile was reported. To define the role of HgdD in protein secretion, we have developed a method to isolate extracellular proteins of Anabaena sp. PCC 7120 wild type and an hgdD loss-of-function mutant. We identified 51 proteins of which the majority is predicted to have an extracellular secretion signal, while few seem to be localized in the periplasmic space. Eight proteins were exclusively identified in the secretome of wild-type cells, which coincides with the distribution of type I secretion signal. We selected three candidates and generated hemagglutinin-tagged fusion proteins which could be exclusively detected in the extracellular protein fraction. However, these proteins are not secreted in the hgdD-mutant background, where they are rapidly degraded. This confirms a direct function of HgdD in protein secretion and points to the existence of a quality control mechanism at least for proteins secreted in an HgdD-dependent pathway.
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Affiliation(s)
- Alexander Hahn
- Institute of Molecular Biosciences, Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9, Frankfurt/am Main, 60438, Germany
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Vilhauer L, Jervis J, Ray WK, Helm RF. The exo-proteome and exo-metabolome of Nostoc punctiforme (Cyanobacteria) in the presence and absence of nitrate. Arch Microbiol 2014; 196:357-67. [PMID: 24643449 DOI: 10.1007/s00203-014-0974-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 02/27/2014] [Indexed: 01/04/2023]
Abstract
The ability of nitrogen-fixing filamentous Cyanobacteria to adapt to multiple environments comes in part from assessing and responding to external stimuli, an event that is initiated in the extracellular milieu. While it is known that these organisms produce numerous extracellular substances, little work has been done to characterize both the metabolites and proteins present under standard laboratory growth conditions. We have assessed the extracellular milieu of Nostoc punctiforme when grown in liquid culture in the presence and absence of a nitrogen source (nitrate). The extracellular proteins identified were enriched in integrin β-propellor domains and calcium-binding sites with sequences unique to N. punctiforme, supporting a role for extracellular proteins in modulating species-specific recognition and behavior processes. Extracellular proteases are present and active under both conditions, with the cells grown with nitrate having a higher activity when normalized to chlorophyll levels. The released metabolites are enriched in peptidoglycan-derived tetrasaccharides, with higher levels in nitrate-free media.
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Affiliation(s)
- Laura Vilhauer
- Department of Biochemistry, Virginia Tech, 143 Life Sciences 1, Blacksburg, VA, 24061-0910, USA
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Park JJ, Lechno-Yossef S, Wolk CP, Vieille C. Cell-specific gene expression in Anabaena variabilis grown phototrophically, mixotrophically, and heterotrophically. BMC Genomics 2013; 14:759. [PMID: 24191963 PMCID: PMC4046671 DOI: 10.1186/1471-2164-14-759] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 10/26/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND When the filamentous cyanobacterium Anabaena variabilis grows aerobically without combined nitrogen, some vegetative cells differentiate into N2-fixing heterocysts, while the other vegetative cells perform photosynthesis. Microarrays of sequences within protein-encoding genes were probed with RNA purified from extracts of vegetative cells, from isolated heterocysts, and from whole filaments to investigate transcript levels, and carbon and energy metabolism, in vegetative cells and heterocysts in phototrophic, mixotrophic, and heterotrophic cultures. RESULTS Heterocysts represent only 5% to 10% of cells in the filaments. Accordingly, levels of specific transcripts in vegetative cells were with few exceptions very close to those in whole filaments and, also with few exceptions (e.g., nif1 transcripts), levels of specific transcripts in heterocysts had little effect on the overall level of those transcripts in filaments. In phototrophic, mixotrophic, and heterotrophic growth conditions, respectively, 845, 649, and 846 genes showed more than 2-fold difference (p < 0.01) in transcript levels between vegetative cells and heterocysts. Principal component analysis showed that the culture conditions tested affected transcript patterns strongly in vegetative cells but much less in heterocysts. Transcript levels of the genes involved in phycobilisome assembly, photosynthesis, and CO2 assimilation were high in vegetative cells in phototrophic conditions, and decreased when fructose was provided. Our results suggest that Gln, Glu, Ser, Gly, Cys, Thr, and Pro can be actively produced in heterocysts. Whether other protein amino acids are synthesized in heterocysts is unclear. Two possible components of a sucrose transporter were identified that were upregulated in heterocysts in two growth conditions. We consider it likely that genes with unknown function represent a larger fraction of total transcripts in heterocysts than in vegetative cells across growth conditions. CONCLUSIONS This study provides the first comparison of transcript levels in heterocysts and vegetative cells from heterocyst-bearing filaments of Anabaena. Although the data presented do not give a complete picture of metabolism in either type of cell, they provide a metabolic scaffold on which to build future analyses of cell-specific processes and of the interactions of the two types of cells.
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Affiliation(s)
- Jeong-Jin Park
- />Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
- />Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824 USA
- />Present address: Institute of Biological Chemistry, Washington State University, Pullman, WA 99164 USA
| | - Sigal Lechno-Yossef
- />Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
- />MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
| | - Coleman Peter Wolk
- />Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
- />MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
- />Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Claire Vieille
- />Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
- />Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824 USA
- />Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824 USA
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Hahn A, Stevanovic M, Mirus O, Lytvynenko I, Pos KM, Schleiff E. The outer membrane TolC-like channel HgdD is part of tripartite resistance-nodulation-cell division (RND) efflux systems conferring multiple-drug resistance in the Cyanobacterium Anabaena sp. PCC7120. J Biol Chem 2013; 288:31192-205. [PMID: 24014018 DOI: 10.1074/jbc.m113.495598] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The TolC-like protein HgdD of the filamentous, heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 is part of multiple three-component "AB-D" systems spanning the inner and outer membranes and is involved in secretion of various compounds, including lipids, metabolites, antibiotics, and proteins. Several components of HgdD-dependent tripartite transport systems have been identified, but the diversity of inner membrane energizing systems is still unknown. Here we identified six putative resistance-nodulation-cell division (RND) type factors. Four of them are expressed during late exponential and stationary growth phase under normal growth conditions, whereas the other two are induced upon incubation with erythromycin or ethidium bromide. The constitutively expressed RND component Alr4267 has an atypical predicted topology, and a mutant strain (I-alr4267) shows a reduction in the content of monogalactosyldiacylglycerol as well as an altered filament shape. An insertion mutant of the ethidium bromide-induced all7631 did not show any significant phenotypic alteration under the conditions tested. Mutants of the constitutively expressed all3143 and alr1656 exhibited a Fox(-) phenotype. The phenotype of the insertion mutant I-all3143 parallels that of the I-hgdD mutant with respect to antibiotic sensitivity, lipid profile, and ethidium efflux. In addition, expression of the RND genes all3143 and all3144 partially complements the capability of Escherichia coli ΔacrAB to transport ethidium. We postulate that the RND transporter All3143 and the predicted membrane fusion protein All3144, as homologs of E. coli AcrB and AcrA, respectively, are major players for antibiotic resistance in Anabaena sp. PCC 7120.
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Affiliation(s)
- Alexander Hahn
- From the Department of Biosciences, Molecular Cell Biology of Plants
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Exploring the size limit of protein diffusion through the periplasm in cyanobacterium Anabaena sp. PCC 7120 using the 13 kDa iLOV fluorescent protein. Res Microbiol 2013; 164:710-7. [DOI: 10.1016/j.resmic.2013.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 05/24/2013] [Indexed: 01/16/2023]
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González A, Valladares A, Peleato ML, Fillat MF. FurA influences heterocyst differentiation in Anabaena sp. PCC 7120. FEBS Lett 2013; 587:2682-90. [PMID: 23851073 DOI: 10.1016/j.febslet.2013.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 07/01/2013] [Accepted: 07/02/2013] [Indexed: 01/14/2023]
Abstract
In Anabaena sp. PCC 7120, FurA is a global transcriptional regulator whose expression is strongly induced by NtcA in proheterocysts and remains stably expressed in mature heterocysts. In the present study, overexpression of furA partially suppressed heterocyst differentiation by impairing morphogenesis at an early stage. Recombinant purified FurA specifically bound in vitro to the promoter regions of ntcA, while quantitative RT-PCR analyses indicated that furA overexpression strongly affected the transient increase of ntcA expression that occurs shortly after nitrogen step-down. Overall, the results suggest a connection between iron homeostasis and heterocyst differentiation via FurA, by modulating the expression of ntcA.
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Affiliation(s)
- Andrés González
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, 50009 Zaragoza, Spain
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Tan H, Wan S, Liu PQ, Wang L, Zhang CC, Chen WL. Alr5068, a Low-Molecular-Weight protein tyrosine phosphatase, is involved in formation of the heterocysts polysaccharide layer in the cyanobacterium Anabaena sp. PCC 7120. Res Microbiol 2013; 164:875-85. [PMID: 23827083 DOI: 10.1016/j.resmic.2013.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 05/14/2013] [Indexed: 11/25/2022]
Abstract
The filamentous cyanobacterium Anabaena sp. PCC 7120 forms nitrogen-fixing heterocysts after deprivation of combined nitrogen. Under such conditions, vegetative cells provide heterocysts with photosynthate and receive fixed nitrogen from the latter. Heterocyst envelope contains a glycolipid layer and a polysaccharide layer to restrict the diffusion of oxygen into heterocysts. Low-Molecular-Weight protein tyrosine phosphatases (LMW-PTPs) are involved in the biosynthesis of exopolysaccharides in bacteria. Alr5068, a protein from Anabaena sp. PCC 7120, shows significant sequence similarity with LMW-PTPs. In this study we characterized the enzymatic properties of Alr5068 and showed that it can dephosphorylate several autophosphorylated tyrosine kinases (Alr2856, Alr3059 and All4432) of Anabaena sp. PCC 7120 in vitro. Several conserved residues among LMW-PTPs are shown to be essential for the phosphatase activity of Alr5068. Overexpression of alr5068 results in a strain unable to survive under diazotrophic conditions, with the formation of morphologically mature heterocysts detached from the filaments. Overexpression of an alr5068 allele that lost phosphatase activity led to the formation of heterocyst with an impaired polysaccharide layer. The alr5068 gene was upregulated after nitrogen step-down and its mutation affected the expression of hepA and hepC, two genes necessary for the formation of the heterocyst envelope polysaccharide (HEP) layer. Our results suggest that Alr5068 is associated with the production of HEP in Anabaena sp. PCC 7120.
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Affiliation(s)
- Hui Tan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, China.
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Hahn A, Stevanovic M, Mirus O, Schleiff E. The TolC-like protein HgdD of the cyanobacterium Anabaena sp. PCC 7120 is involved in secondary metabolite export and antibiotic resistance. J Biol Chem 2012; 287:41126-38. [PMID: 23071120 DOI: 10.1074/jbc.m112.396010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The role of TolC has largely been explored in proteobacteria, where it functions as a metabolite and protein exporter. In contrast, little research has been carried out on the function of cyanobacterial homologues, and as a consequence, not much is known about the mechanism of cyanobacterial antibiotic uptake and metabolite secretion in general. It has been suggested that the TolC-like homologue of the filamentous, heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, termed heterocyst glycolipid deposition protein D (HgdD), is involved in both protein and lipid secretion. To describe its function in secondary metabolite secretion, we established a system to measure the uptake of antibiotics based on the fluorescent molecule ethidium bromide. We analyzed the rate of porin-dependent metabolite uptake and confirmed the functional relation between detoxification and the action of HgdD. Moreover, we identified two major facilitator superfamily proteins that are involved in this process. It appears that anaOmp85 (Alr2269) is not required for insertion or assembly of HgdD, because an alr2269 mutant does not exhibit a phenotype similar to the hgdD mutant. Thus, we could assign components of the metabolite efflux system and describe parameters of detoxification by Anabaena sp. PCC 7120.
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Affiliation(s)
- Alexander Hahn
- Department of Biosciences, Center of Membrane Proteomics, Cluster of Excellence Frankfurt, Goethe University, 60438 Frankfurt, Germany
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Impairment of O-antigen production confers resistance to grazing in a model amoeba-cyanobacterium predator-prey system. Proc Natl Acad Sci U S A 2012; 109:16678-83. [PMID: 23012457 DOI: 10.1073/pnas.1214904109] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The grazing activity of predators on photosynthetic organisms is a major mechanism of mortality and population restructuring in natural environments. Grazing is also one of the primary difficulties in growing cyanobacteria and other microalgae in large, open ponds for the production of biofuels, as contaminants destroy valuable biomass and prevent stable, continuous production of biofuel crops. To address this problem, we have isolated a heterolobosean amoeba, HGG1, that grazes upon unicellular and filamentous freshwater cyanobacterial species. We have established a model predator-prey system using this amoeba and Synechococcus elongatus PCC 7942. Application of amoebae to a library of mutants of S. elongatus led to the identification of a grazer-resistant knockout mutant of the wzm ABC O-antigen transporter gene, SynPCC7942_1126. Mutations in three other genes involved in O-antigen synthesis and transport also prevented the expression of O-antigen and conferred resistance to HGG1. Complementation of these rough mutants returned O-antigen expression and susceptibility to amoebae. Rough mutants are easily identifiable by appearance, are capable of autoflocculation, and do not display growth defects under standard laboratory growth conditions, all of which are desired traits for a biofuel production strain. Thus, preventing the production of O-antigen is a pathway for producing resistance to grazing by certain amoebae.
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Staron P, Maldener I. All0809/8/7 is a DevBCA-like ABC-type efflux pump required for diazotrophic growth in Anabaena sp. PCC 7120. MICROBIOLOGY-SGM 2012; 158:2537-2545. [PMID: 22859614 DOI: 10.1099/mic.0.058909-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Efflux pumps export a wide variety of proteinaceous and non-proteinaceous substrates across the Gram-negative cell wall. For the filamentous cyanobacterium Anabaena sp. strain PCC 7120, the ATP-driven glycolipid efflux pump DevBCA-TolC has been shown to be crucial for the differentiation of N(2)-fixing heterocysts from photosynthetically active vegetative cells. In this study, a homologous system was described. All0809/8/7-TolC form a typical ATP-driven efflux pump as shown by surface plasmon resonance. This putative exporter is also involved in diazotrophic growth of Anabaena sp. PCC 7120. A mutant in all0809 encoding the periplasmic membrane fusion protein of the pump was not able to grow without combined nitrogen. Although heterocysts of this mutant were not distinguishable from those of the wild-type in light and electron micrographs, they were impaired in providing the microoxic environment necessary for N(2) fixation. RT-PCR of all0809 transcripts and localization studies on All0807-GFP revealed that All0809/8/7 was initially downregulated during heterocyst maturation and upregulated at later stages of heterocyst formation in all cells of the filament. A substrate of the efflux pump could not be identified in ATP hydrolysis assays. We discuss a role for All0809/8/7-TolC in maintaining the continuous periplasm and how this would be of special importance for heterocyst differentiation.
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Affiliation(s)
- Peter Staron
- Department of Microbiology/Organismic Interactions, IMIT - Institute of Microbiology and Infection Medicine Tübingen, University of Tübingen, 72076 Tübingen, Germany
| | - Iris Maldener
- Department of Microbiology/Organismic Interactions, IMIT - Institute of Microbiology and Infection Medicine Tübingen, University of Tübingen, 72076 Tübingen, Germany
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